Are there some permissions files about the `jmpi` instruction
I am studying how Linux works. I encountered a strange instruction assembly language jmpi
. I can find some explanation on various sites, but oddly enough I cannot find it in assembler, including the Intel® 64 and IA-32 Software Developer's Guide . I was looking for a book, but it doesn't contain instructions jmpi
. I think the Intel manual should be the most authoritative book in Intel assembler. So this is very strange.
My question is, are there any books or authority files that document this instruction?
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There are several instructions in the Intel processor instruction set JMP
. They have the same intended result, but differ in the type of operand they take: 8-bit constant, 16-bit constant, 32-bit constant, value specified indirectly; is also a relative or absolute jump. See Table from item 854 of the architecture guide.
Opcode Instruction Description
------+------------+----------------------------
EB cb JMP rel8 Jump short
E9 cw JMP rel16 Jump near, relative
E9 cd JMP rel32 Jump near, relative
FF /4 JMP r/m16 Jump near, absolute indirect
FF /4 JMP r/m32 Jump near, absolute indirect
FF /4 JMP r/m64 Jump near, absolute indirect
EA cd JMP ptr16:16 Jump far, absolute
...
They are viewed in different ways as a legacy of different memory models supported at different stages of architecture development.
Many builders introduce additional mnemonics to make the assembly code more readable. Thus, the as86
instruction JMPI
refers to the closest JMP
, it can be either absolute or relative, but must always remain inside the code segment, the interpolation jump. as86
is the only authoritative link.
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